Cruise Control System - Cruise Control Switch Circuit

Lexus IS250 IS220d GSE20 ALE20 - CRUISE CONTROL

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE ON INTELLIGENT TESTER

INSPECT CRUISE CONTROL MAIN SWITCH

CHECK HARNESS AND CONNECTOR (CRUISE CONTROL MAIN SWITCH - SPIRAL CABLE)

CHECK SPIRAL CABLE

CHECK WIRE HARNESS (SPIRAL CABLE - ECM AND BODY GROUND)

CRUISE CONTROL SYSTEM - Cruise Control Switch Circuit

DESCRIPTION

The cruise control main switch operates 7 functions: SET, - (COAST), TAP-DOWN, RES (RESUME), + (ACCEL), TAP-UP, and CANCEL. The SET, TAP-DOWN, and - (COAST) functions, and the RES (RESUME), TAP-UP, and + (ACCEL) functions are operated with the same switch. The cruise control main switch is an automatic return type switch which turns on only while operating it in the direction of each arrow and turns off after releasing it. The internal contact point of the cruise control main switch is turned on with the switch operation. Then the ECM reads the voltage value that has been changed by the switch operation to control SET, - (COAST), RES (RESUME), + (ACCEL), and CANCEL.


WIRING DIAGRAM

Cruise Control System - Cruise Control Switch Circuit. CRUISE CONTROL. Lexus IS250 IS220d GSE20 ALE20

INSPECTION PROCEDURE

1.READ VALUE ON INTELLIGENT TESTER
Cruise Control System - Cruise Control Switch Circuit. CRUISE CONTROL. Lexus IS250 IS220d GSE20 ALE20

Connect the intelligent tester to the DLC3.

Turn the engine switch on (IG) and turn the intelligent tester main switch on.

Check the DATA LIST for proper functioning of the cruise control main switch.

ECM (Cruise control):
ItemMeasurement Item/Display (Range)Normal ConditionDiagnostic Note
MAIN SW (MAIN)Main switch signal (Main CPU)/ON or OFFON: Main switch on (Pushed on)
OFF: Main switch off (Pushed off)
-
CANCEL SWCANCEL switch signal/ON or OFFON: CANCEL switch on
OFF: CANCEL switch off
-
SET/COAST SWSET/COAST switch signal/ON or OFFON: - (COAST)/SET switch on
OFF: - (COAST)/SET switch off
-
RES/ACC SWRES/ACC switch signal/ON or OFFON: + (ACCEL)/RES (RESUME) switch on
OFF: + (ACCEL)/RES (RESUME) switch off
-
  • OK:
  • When the cruise control main switch is operated, the display changes as shown above.
  • Result:
    ResultProceed to
    OKA
    NG (All items are defective)B
    NG (1 to 3 items are defective)C
A
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
C
REPLACE CRUISE CONTROL MAIN SWITCH
B
2.INSPECT CRUISE CONTROL MAIN SWITCH

Remove the cruise control main switch .

Measure the resistance according to the value(s) in the table below.

Cruise Control System - Cruise Control Switch Circuit. CRUISE CONTROL. Lexus IS250 IS220d GSE20 ALE20

  • Standard resistance:
  • Tester ConnectionSwitch ConditionSpecified Condition
    A-1 (CCS) - A-3 (ECC)Neutral10 kΩ or higher
    A-1 (CCS) - A-3 (ECC)+ (ACCEL)/RES (RESUME)216 to 264 Ω
    A-1 (CCS) - A-3 (ECC)- (COAST)/SET567 to 693 Ω
    A-1 (CCS) - A-3 (ECC)CANCEL1,386 to 1,694 Ω
    A-1 (CCS) - A-3 (ECC)Main Switch off10 kΩ or higher
    A-1 (CCS) - A-3 (ECC)Main Switch onBelow 1 Ω
NG
REPLACE CRUISE CONTROL MAIN SWITCH
OK
3.CHECK HARNESS AND CONNECTOR (CRUISE CONTROL MAIN SWITCH - SPIRAL CABLE)
Cruise Control System - Cruise Control Switch Circuit. CRUISE CONTROL. Lexus IS250 IS220d GSE20 ALE20

Disconnect the m1 connector from the spiral cable.

Measure the resistance according to the value(s) in the table below.

Standard resistance
Tester connectionSpecified condition
A-1 - m1-3Below 1 Ω
A-3 - m1-4Below 1 Ω
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
4.CHECK SPIRAL CABLE
Cruise Control System - Cruise Control Switch Circuit. CRUISE CONTROL. Lexus IS250 IS220d GSE20 ALE20
  • NOTICE:
  • The spiral cable is an important part of the SRS airbag system. Incorrect removal or installation of the spiral cable may prevent the airbag from deploying. Be sure to read the page shown in the brackets.
  • HINT:
Removal
Installation

Remove the spiral cable.

Measure the resistance according to the value(s) in the table below.

Standard resistance
Tester ConnectionSpiral Cable PositionSpecified Condition
m1-3 - J24-1 (CCS)CenterBelow 1 Ω
2.5 rotations to the left
2.5 rotations to the right
m1-4 - J24-2 (ECC)CenterBelow 1 Ω
2.5 rotations to the left
2.5 rotations to the right
  • HINT:
  • The spiral cable makes a maximum of approximately 5 rotations.
NG
REPLACE SPIRAL CABLE
OK
5.CHECK WIRE HARNESS (SPIRAL CABLE - ECM AND BODY GROUND)
Cruise Control System - Cruise Control Switch Circuit. CRUISE CONTROL. Lexus IS250 IS220d GSE20 ALE20

Measure the resistance according to the value(s) in the table below.

  • Standard resistance:
  • Tester ConnectionConditionSpecified Condition
    J24-1 - A6-31 (CCS)AlwaysBelow 1 Ω
    A6-31 (CCS) - Body groundAlways10 kΩ or higher
    J24-2 (ECC) - Body groundAlwaysBelow 1 Ω
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
REPLACE ECM